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United States Patent |
5,058,574
|
Anderson
,   et al.
|
October 22, 1991
|
Therapeutic limb brace
Abstract
A therapeutic limb brace for gradually extending flexion contractures of a
patient's knee or elbow, and for increasing dorsiflexion of the foot.
Upper and lower frames of the brace are incrementally adjustable in both
length and lateral spacing for fitting limbs of various proportions, the
frames having side members that are comfortably spaced apart from the
limb. Control of knee joint movement, for example, is provided by one or
more tension springs that can be selectively hooked in parallel between
the upper and middle frames for dynamic therapy, a stop member for
preventing hyperextension, and a plurality of index holes that can be used
in static therapy for locking the frames in fixed angular relation or for
limiting movement to a selected angular range. A turnbuckle substituted
for one of the springs provides gradual movement at high mechanical
advantage. A cable and sheave tackle assembly having series-connected
springs can replace the direct parallel spring connections for simplifying
the wearing and adjustment of the brace by the user. A lower frame for
controlled foot support has a padded base, front and rear blocks for
lateral confinement, and adjustable front, instep and heel straps for
holding the foot in place, the heel strap having a cup member for holding
the heel down .A plurality of tension spring connections between the
middle and lower frames permits dynamic inducement of dorsiflexion; static
control is provided by a substituted turnbuckle. An ankle strap provides
controlled prevention of either inversion or eversion as needed.
Inventors:
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Anderson; Lucinda L. (2396 Mountain Woods, Colton, CA 92324);
Anderson; Christopher D. (1250 Root Rd., Modesto, CA 95351)
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Appl. No.:
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542162 |
Filed:
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June 22, 1990 |
Current U.S. Class: |
602/16; 602/20; 602/26 |
Intern'l Class: |
A61F 005/01; A61F 005/00; A61F 005/04 |
Field of Search: |
128/77,80 R,80 C,80 H,80 F,87 R,88,80 E
36/11.5,7.5,69,118,92,105,125
|
References Cited
U.S. Patent Documents
2267848 | Dec., 1941 | Taylor | 128/80.
|
2573866 | Nov., 1951 | Murphy.
| |
2772674 | Dec., 1956 | Swiech et al.
| |
3805773 | Apr., 1974 | Sichau.
| |
4370977 | Feb., 1983 | Mauldin et al.
| |
4414965 | Nov., 1983 | Mauldin et al. | 128/87.
|
4433679 | Feb., 1984 | Gautlin et al. | 128/80.
|
4456003 | Jun., 1984 | Allard et al.
| |
4489718 | Dec., 1984 | Martin.
| |
4494534 | Jan., 1985 | Hutson | 128/88.
|
4624246 | Nov., 1986 | Ajemian.
| |
4688559 | Aug., 1987 | Vito et al.
| |
4817588 | Apr., 1989 | Bledsoe | 128/80.
|
4919118 | Apr., 1990 | Morris | 128/88.
|
Foreign Patent Documents |
410500 | Dec., 1909 | FR | 36/125.
|
2447184 | Sep., 1980 | FR | 128/80.
|
1489762 | Jun., 1989 | SU | 128/80.
|
2215213A | Sep., 1989 | GB | 128/80.
|
Other References
LMB Rehab Products, Inc. 1988 Catalog, 1988, pp. 1-20.
"Dynamic Elbow Extension Brace" advertisement, Anderson Enterprises,
Modesto, Calif., 1 page, no date.
"Dynamic Elbow Brace" flyer, Anderson Enterprises, Modesto, Calif., 2
pages, no date.
|
Primary Examiner: Apley; Richard J.
Assistant Examiner: Horowitz; Karen G.
Attorney, Agent or Firm: Sheldon & Mak
Claims
What is claimed is:
1. An adjustable therapeutic brace comprising:
(a) an upper frame comprising:
(i) right and left rigid upper frame portions;
(ii) at least one rigid upper cross frame portion for rigidly connecting
the upper frame portions in parallel spaced relation;
(iii) means for connecting the upper frame portions in spaced relation to
opposite sides of an upper limb portion of a user;
(b) a middle frame comprising:
(i) right and left rigid middle frame portions;
(ii) at least one rigid middle cross frame portion rigidly connecting the
middle frame portions in parallel spaced relation;
(iii) means for connecting the middle frame portions in spaced relation to
opposite sides of a middle limb portion of the user;
(c) right and left first hinge means for pivotally connecting the upper
frame to the middle frame relative to a first hinge axis, the middle frame
being movable from a flexion position to an extension position relative to
the upper frame, the first hinge axis being located for intersecting a
first limb joint of the user; and
(d) first limiting means for selectively limiting movement of the middle
frame about the first hinge axis relative to the upper frame comprising
first sheave means and tension means mounted between the right and left
frame portions.
2. The apparatus of claim 1 wherein at least one of the upper and middle
frame portions comprises an upper frame member and a lower frame member,
and means for selectively rigidly connecting the frame members in
overlapping parallel relation for obtaining a desired effective length of
the upper and middle frame portions.
3. The apparatus of claim 1, wherein each of the cross frame portions
includes means for selectively defining a separation between opposite ends
thereof for adjustably spacing the frame portions from the user's limb
portions.
4. The apparatus of claim 1, wherein the means for connecting the frame
portions relative to the user's limb portions comprises a plurality of
spaced apart limb strap assemblies connected to each of the upper and
middle frame portions.
5. The apparatus of claim 4, wherein at least some of the limb strap
assemblies each comprise front and rear adjustable buckle means for
providing opening and closure of the respective strap assemblies, as well
as adjustment of same, selectively from both the front and rear of the
user.
6. The apparatus of claim 4, wherein each of at least some of the limb
strap assemblies comprises:
(a) an adjustable limb strap for enclosing the limb portion; and
(b) a pair of anchor straps, each anchor strap connecting the limb strap to
one of the right and left frame portions for support of the limb strap in
spaced relation to the frame portions.
7. The apparatus of claim 1, wherein the first limiting means comprises
means for selectively locking the first hinge means into one of a
plurality of angularly spaced positions.
8. The apparatus of claim 7, wherein the means for selectively locking the
first hinge means comprises:
(a) a plate member fixed on one of the upper and middle frames, the plate
member forming a plurality of spaced engagement surfaces, the engagement
surfaces being equidistant from the first hinge axis; and
(b) means for locating an engagement member in fixed relation to the other
of the upper and middle frames, the engagement member being in locating
engagement with a selected one of the engagement surfaces.
9. The apparatus of claim 8, wherein each of the upper frame portions forms
one of the plate members, and each of the middle frame portions includes
means for locating the corresponding engagement members.
10. The apparatus of claim 9, wherein the means for locating the engagement
members comprises an engagement passage in each of the middle frame
portions, the engagement passage being located in line with the upper
frame in the extension position, and opposite the first hinge axis from
the means for connecting the middle frame portions to the middle limb
portion.
11. The apparatus of claim 8, wherein each of the engagement surfaces forms
a cylindrical passage between opposite sides of one of the frame portions.
12. The apparatus of claim 1, wherein the first limiting means comprises
means for selectively connecting extension biasing means between the upper
frame and the middle frame for urging the middle frame toward the
extension position.
13. The apparatus of claim 12, wherein the means for selectively connecting
extension biasing means comprises:
(a) first sheave means mounted to one of the upper and middle frames
between the right and left frame portions thereof, and offset from the
first hinge axis for clearing the user's limb;
(b) a flexible tension member movably engaging the sheave means;
(c) a first biasing member connected between the tension member and one of
the upper and middle frames; and
(d) means for connecting the tension member to the other of the upper and
middle frames.
14. The apparatus of claim 13, comprising at least two parallel-connected
counterparts of the series-connected first sheave means, the tension
member, and one of the first biasing members.
15. The apparatus of claim 1, further comprising stop means for preventing
movement of the middle frame beyond a stop extremity angle about the first
hinge axis relative to the upper frame.
16. The apparatus of claim 15, wherein the stop means comprises a stop
member on one of the upper and middle frames, the stop member engaging the
other of the frames in the extension position.
17. The apparatus of claim 15, wherein the stop means comprises:
(a) a plate member fixed on one of the upper and middle frames, the plate
member forming a plurality of spaced engagement surfaces; and
(b) a stop member for engagement by a selected one of the engagement
surfaces, the stop member preventing movement of the other frame member in
one direction relative thereto by contact therewith.
18. The apparatus of claim 1, further comprising a lower frame connected to
the middle frame, the lower frame including a base for supporting a limb
extremity of the user.
19. The apparatus of claim 18, further comprising second hinge means
whereby the lower frame is pivotably connected to the middle frame
relative to a second hinge axis.
20. The apparatus of claim 19, wherein an effective length of the middle
frame portion is changeable for selecting a desired distance between the
first hinge axis and the second hinge axis.
21. The apparatus of claim 19, further comprising means for controlling an
extremity angular position of the lower frame relative to the middle frame
about the second hinge axis.
22. The apparatus of claim 21, wherein the means for controlling the lower
frame comprises coupling means for connecting the lower frame and the
middle frame along a coupling axis, the coupling axis being displaced to
one side of the second hinge axis and having a connection component in a
plane normal to the second hinge axis.
23. The apparatus of claim 22, wherein the coupling means comprises a
turnbuckle assembly, the turnbuckle assembly being pivotally connected
between the lower frame and the middle frame for locking the lower frame
in a predetermined angular position relative to the middle frame.
24. The apparatus of claim 22, wherein the coupling means comprises means
for selectively connecting extremity biasing means between the lower frame
to the middle frame for biasing the extremity angular position toward an
extremity rest angle.
25. The apparatus of claim 24, wherein the means for selectively connecting
extremity biasing means comprises a plurality of eye members rigidly
connected to each of the middle frame and the lower frame for sequentially
connecting a plurality of biasing members therebetween, each of the
biasing members providing a portion of a total biasing moment.
26. The apparatus of claim 22, wherein the coupling means comprises range
limiting means for adjustably limiting a range of travel of the base about
the second hinge axis.
27. The apparatus of claim 26, wherein the range limiting means comprises
cushion biasing means for cushioning a flexion limit of the range of
travel of the base about the second hinge axis.
28. The apparatus of claim 19, wherein the base is adapted for supporting a
foot of the user, the second hinge means including right and left second
hinge portions, the second hinge portions being located for straddling an
ankle joint of the user.
29. An adjustable therapeutic brace comprising:
(a) an upper frame comprising:
(i) right and left upper frame portions; and
(ii) means for connecting the upper frame portions in spaced relation to
opposite sides of an upper limb portion of a user;
(b) a middle frame comprising:
(i) right and left middle frame portions; and
(ii) means for connecting the middle frame portions in spaced relation to
opposite sides of a middle limb portion of the user;
(c) right and left first hinge means for pivotally connecting the upper
frame to the middle frame relative to a first hinge axis, the middle frame
being movable from a flexion position to an extension position relative to
the upper frame; and
(d) first limiting means for selectively limiting movement of the middle
frame about the first hinge axis relative to the upper frame, the first
limiting means comprising means for selectively connecting extension
biasing means between the upper frame and the middle frame for urging the
middle frame toward the extension position, the means for selectively
connecting extension biasing means comprising:
(i) first sheave means mounted in fixed relation to one of the upper and
middle frames and the axis of which is offset from the first hinge axis;
(ii) a flexible tension member movably engaging the sheave means;
(iii) a first biasing member connected between the tension member and one
of the upper and middle frames;
(iv) means for connecting the tension member to the other of the upper and
middle frames;
(v) second sheave means fixedly located on the other of the upper and
middle frames and spaced from the first sheave means, the tension member
movably engaging the second sheave means; and
(vi) a second biasing member connected between the tension member and the
one of the upper and middle frames.
30. The apparatus of claim 29, further comprising turnbuckle means
connected in series with the tension member for adjusting an overall
length of the tension member and the biasing members of the extension
biasing means.
31. The apparatus of claim 29, further comprising third sheave means
fixedly located on the one of the upper and middle frames and spaced from
the first sheave means, the tension member movably engaging the third
sheave means.
32. An adjustable therapeutic brace comprising:
(a) an upper frame comprising:
(i) right and left upper frame portions; and
(ii) means for connecting the upper frame portions in spaced relation to
opposite sides of an upper limb portion of a user;
(b) a middle frame comprising:
(i) right and left middle frame portions; and
(ii) means for connecting the middle frame portions in spaced relation to
opposite sides of a middle limb portion of the user;
(c) right and left first hinge means for pivotally connecting the upper
frame to the middle frame relative to a first hinge axis, the middle frame
being movable from a flexion position to an extension position relative to
the upper frame;
(d) first limiting means for selectively limiting movement of the middle
frame about the first hinge axis relative to the upper frame comprising
first sheave means and tension means mounted between the right and left
frame portions;
(e) a lower frame connected to the middle frame, the lower frame including
a base for supporting a foot of the user;
(f) second hinge means whereby the lower frame is pivotably connected to
the middle frame relative to a second hinge axis, the second hinge means
including right and left second hinge portions, the second hinge portions
being located for straddling an ankle joint of the user;
(g) a pair of spaced apart heel anchor members fixably connected to the
base of the lower frame;
(h) a cup-shaped member for application to a heel portion of the user's
foot; and
(i) means for supporting opposite extremities of the cup-shaped member from
the heel anchor members, the cup-shaped member being located opposite the
second hinge means from the heel anchor members for preventing movement of
the heel portion away from the base.
33. The apparatus of claim 32, further comprising means for adjusting a
distance between the cup-shaped member and the second hinge axis,
including a pair of flexible heel strap members connected to the
cup-shaped member, each heel strap member extending ahead of one of the
second hinge portions for support therefrom.
34. An adjustable therapeutic brace comprising:
(a) an upper frame comprising:
(i) right and left upper frame portions; and
(ii) means for connecting the upper frame portions in spaced relation to
opposite sides of an upper limb portion of a user;
(b) a middle frame comprising:
(i) right and left middle frame portions; and
(ii) means for connecting the middle frame portions in spaced relation to
opposite sides of a middle limb portion of the user;
(c) right and left first hinge means for pivotally connecting the upper
frame to the middle frame relative to a first hinge axis, the middle frame
being movable from a flexion position to an extension position relative to
the upper frame;
(d) first limiting means for selectively limiting movement of the middle
frame about the first hinge axis relative to the upper frame comprising
first sheave means and tension means mounted between the right and left
frame portions;
(e) a lower frame connected to the middle frame, the lower frame including
a base for supporting a foot of the user;
(f) second hinge means whereby the lower frame is pivotably connected to
the middle frame relative to a second hinge axis, the second hinge means
including right and left second hinge portions, the second hinge portions
being located for straddling an ankle joint of the user; and
(g) an ankle pad member for axially supporting the ankle joint from a
selected one of the hinge portions, for selectively preventing eversion
and inversion of the user's foot.
35. The apparatus of claim 34, further comprising ankle fastener means for
adjustably connecting the ankle pad member to the hinge portion.
Description
BACKGROUND
The present invention relates to braces used in a clinical setting for
rehabilitation of flexion and extension contractures of the knee, ankle,
and elbow after neurologic or orthopedic injury.
Braces of the prior art are typically designed for prevention of
contractures or immobilization of joints. Conventional braces have metal
side frames for positioning along opposite sides of a patient's limb, and
a plurality of straps for securing the frames to the limb. The frames have
articulated joints for permitting movement of associated limb joints of
the patient. The joints can be lockable or equipped with biasing means for
resisting movement.
A problem with existing braces is the difficulty in fitting them to varying
shapes and sizes of the extremities because the straps are attached
directly to the metal framework. This also increases the potential for the
development of pressure sores where the frame is pulled into contact with
soft tissues.
Another problem is that the braces are generally not suitable for treating
existing contractures because they do not exert sufficient force to extend
flexion contractures or to rehabilitate to a functional range of motion.
Also, in leg braces that include foot support, there is no satisfactory
control of inversion or eversion of the foot. Also, existing braces for
ambulatory patients (walking braces) use the patient's shoe belted into
the brace. Thus it is not practical to wear such braces either with or
without a shoe.
Thus there is a need for a brace that not only will statically flex and
immobilize and both statically and dynamically extend a user's limb, but
will produce a variable dynamic force of a sufficient degree to extend a
severe flexion contracture.
SUMMARY
The present invention is directed to an improved adjustable therapeutic
brace that meets this need. The brace includes upper and middle frames,
each frame having right and left rigid frame portions and each having at
least one cross frame member for rigidly connecting the corresponding
upper and middle frame portions in parallel spaced relation, and means for
connecting the upper and middle frame portions in spaced relation to
opposite sides of a user's limb; right and left first hinge means for
pivotally connecting the upper frame to the middle frame relative to a
first hinge axis, the middle frame being movable from a flexion position
to an extension position relative to the upper frame; and first limiting
means for selectively limiting movement of the middle frame about the
first hinge axis relative to the upper frame. Preferably, at least one of
the upper and middle frame portions includes an upper frame member and a
lower frame member, and means for selectively rigidly connecting the frame
members in overlapping parallel relation for obtaining a desired effective
length of the upper and middle frame. Each cross frame portion can include
means for selectively defining a separation between opposite sides thereof
for adjustably spacing the frame portions from the user's limb portions.
The means for connecting the frame portions relative to the user's limb
portions can include a plurality of spaced apart limb strap assemblies
connected to each of the upper and middle frame portions. Preferably, at
least some of the limb strap assemblies include front and rear adjustable
buckle means for providing opening and closure of the respective strap
assemblies, as well as adjustment of same, selectively from both the front
and rear of the user, at least some of the limb strap assemblies each
including an adjustable limb strap for enclosing the limb portion, and a
pair of anchor straps, each connecting the limb strap to one of the right
and left frame portions for support of the limb strap in spaced relation
to the frame portions.
The first limiting means can include means for selectively locking the
first hinge means into one of a plurality of angularly spaced positions,
the means for locking the first hinge means including a plate member fixed
on one of the upper and middle frames for forming a plurality of spaced
engagement surfaces which can be equidistant from the first hinge axis,
and means for locating an engagement member in fixed relation to the other
of the upper and middle frames and being in locating engagement with a
selected one of the engagement surfaces.
Each of the upper frame portions can form one of the plate members, and
each of the middle frame portions can include means for locating the
corresponding engagement members. The means for locating the engagement
members can include an engagement passage in each of the middle frame
portions which can be located in line with the upper frame in the
extension position, and opposite the first hinge axis from the means for
connecting the middle frame portions to the middle limb portion. Each of
the engagement surfaces can form a cylindrical passage between opposite
sides of one of the frame portions. Preferably, the first limiting means
includes means for selectively connecting extension biasing means between
the upper frame and the middle frame for urging the middle frame toward
the extension position. The means for selectively connecting extension
biasing means can include a plurality of eye members rigidly connected to
each of the upper frame and middle frame for sequentially connecting a
plurality of biasing members therebetween, each of the biasing members
providing a portion of a total biasing moment.
The means for selectively connecting extension biasing means can include
first sheave means mounted in fixed relation to one of the upper and
middle frames and offset from the first hinge axis, a flexible tension
member movably engaging the sheave means, a first biasing member connected
between the tension member and one of the upper and middle frames, and
means for connecting the tension member to the other of the upper and
middle frames. The means for selectively connecting extension biasing
means can also include second sheave means fixedly located on the other of
the upper and middle frames and spaced from the first sheave means, the
tension member movably engaging the second sheave means, and a second
biasing member connected between the tension member and the one of the
upper and middle frames. Preferably, the means for selectively connecting
extension biasing means includes turnbuckle means connected in series with
the tension member for adjusting an overall length of the tension member
and the biasing members of the extension biasing means. Also, the means
for selectively connecting extension biasing means can further include
third sheave means fixedly located on one of the upper and middle frames,
portions of the tension member serially passing over the first, second,
and third sheave means.
In another preferred configuration of the means for connecting extension
biasing means, there are two parallel connected counterparts of at least
the first sheave means, a portion of the tension member, and one of the
biasing members.
Preferably, the brace includes stop means for preventing movement of the
middle frame beyond a stop extremity angle about the first hinge axis
relative to the upper frame. The stop means can include a stop member on
one of the upper and middle frames, the stop member engaging the other of
the frames in the extension position. The stop means can further include a
plate member fixed on one of the upper and middle frames forming a
plurality of spaced engagement surfaces, and a stop member for engagement
by a selected one of the engagement surfaces for preventing movement of
the other frame member in one direction relative thereto by contact
therewith.
The brace can further include a lower frame connected to the middle frame
and having a base for supporting a limb extremity of the user. Second
hinge means can also be included whereby the lower frame is pivotably
connected to the middle frame relative to a second hinge axis. An
effective length of the middle frame portion is preferably changeable for
selecting a desired distance between the first hinge axis and the second
hinge axis. The brace can include means for controlling an extremity
angular position of the lower frame relative to the middle frame about the
second hinge axis. Preferably the means for controlling the lower frame
can include coupling means for connecting the lower frame and the middle
frame along a coupling axis, the coupling axis being displaced to one side
of the second hinge axis and having a connection component in a plane
normal to the second hinge axis. The coupling means can include a
turnbuckle assembly which is pivotally connected between the lower frame
and middle frame for locking the lower frame in a predetermined angular
position relative to the middle frame. The coupling means can also include
means for selectively connecting extremity biasing means between the lower
frame to the middle frame for biasing the extremity angular position
toward an extremity rest angle. The means for selectively connecting
extremity biasing means preferably includes a plurality of eye members
rigidly connected to each of the middle frame and the lower frame for
sequentially connecting a plurality of biasing members therebetween, each
of the biasing members providing a portion of a total biasing moment.
Further, the coupling means can include range limiting means for adjustably
limiting a range of travel of the lower frame about the second hinge axis.
Preferably the range limiting means includes cushion biasing means for
cushioning a flexion limit of the range of travel.
The base can be adapted for supporting a foot of the user, and the second
hinge means including right and left second hinge portions being located
for straddling an ankle joint of the user. The brace can further include a
pair of spaced apart heel anchor members fixably connected to the base of
the lower frame, a cup shaped member for application to a heel portion of
the user's foot, and means for supporting opposite extremities of the
cup-shaped member from the heel anchor members, the cup-shaped member
being located opposite the second hinge means from the heel anchor members
for preventing movement of the heel portion away from the base. The
extremities of the cup-shaped member can include flexible heel strap
members, each extending ahead of one of the second hinge portions for
support therefrom. Preferably, the base further includes an ankle pad
member for axially supporting the ankle joint by a selected one of the
hinge portions for selectively preventing eversion and inversion of the
user's foot. Also, ankle fastener means can be included for adjustably
connecting the ankle pad member to the hinge portion.
DRAWINGS
These and other features, aspects, and advantages of the present invention
will become better understood with reference to the following description,
appended claims, and accompanying drawings, where:
FIG. 1 is a side elevational view of an adjustable therapeutic limb brace
according to the present invention;
FIG. 2 is a front elevational view of the brace of FIG. 1;
FIG. 3 is a bottom plan view of the brace of FIG. 1;
FIG. 4 is a sectional bottom plan view of the brace of FIG. 1 on line 4--4
of FIG. 2;
FIG. 5 is an exploded sectional view of the apparatus of FIG. 1 on line
5--5 of FIG. 4;
FIG. 6 is an exploded sectional view of the apparatus of FIG. 1 on line
6--6 of FIG. 2;
FIG. 7 is a left rear oblique elevational perspective detail view of the
brace of FIG. 1;
FIG. 8 is a fragmentary side elevational view showing the brace of FIG. 1
in a flexed position; and
FIG. 9 is a side elevational view showing an alternative configuration of
the brace of FIG. 1;
FIG. 10 is a side elevational view showing another alternative
configuration of the brace of FIG. 1;
FIG. 11 is a front elevational view showing further alternative
configuration of the brace of FIG. 1;
FIG. 12 is a fragmentary side elevational view of the apparatus of FIG. 11.
DESCRIPTION
The present invention is directed to a therapeutic limb brace that is
particularly versatile, effective, and easy to use. With reference to the
drawings, and FIGS. 1-5 in particular, a brace apparatus 10 is applied to
a user's limb or leg 11, the leg 11 including an upper limb or thigh 12, a
lower limb or leg 14, and a limb extremity or foot 16, the thigh 12 and
the lower leg 14 being joined by a limb joint or knee 18, the lower leg 14
and the foot 16 being joined by an extremity joint or ankle 20. The
apparatus 10 includes an upper frame 22, a middle frame 24, and a lower
frame 26, the upper and middle frames 22 and 24 being pivotably connected
on a transverse first hinge or knee axis 28, the middle and lower frames
24 and 26 being pivotably connected on a transverse second hinge or ankle
axis 30.
The upper frame 22 includes a spaced pair of elongate upper frame members
32a and lower frame members 32b, each upper frame member 32a being
removably connected in selectable overlapping relation to a corresponding
one of the lower frame members 32b. The frame members 32 and 32b are
clamped in rigid axial alignment by, a plurality of frame fasteners 33 for
forming an upper right frame 34 and an upper left frame 36, the length of
the frames 34 and 36 being adjustable in increments l according to the
spacing of a series of frame holes 37 in which the frame fasteners 33 are
selectively located for fitting variously sized users. The upper right and
left frames 34 and 36 are rigidly connected by an upper bridge member 38
that is fastened to the upper frame members 32a by counterparts of the
frame fasteners 33, the bridge member 38 spacing apart the frames 34 and
36 sufficiently for generously clearing opposite sides of the user's
thigh. The bridge member 38 includes a left bridge portion 38a and a right
bridge portion 38b, the bridge portions 38a and 38b each having an array
of bridge holes 39 and being removably connected in rigid overlapping
relation to each other by additional ones of the frame fasteners 33 that
engage selected pairs of the holes 39, thereby providing adjustable
spacing between the upper right and left frames 34 and 36 for
accommodating the thigh 12 of variously sized users. The upper frame 22 is
secured to the user's thigh 12 by a pair of limb strap assemblies 40,
designated 40a and 40b and further described below, the strap assemblies
40a and 40b locating the upper right and left frames 34 and 36 spaced away
from opposite sides of the user's thigh 12.
In similar fashion, the middle frame 24 includes a spaced pair of elongate
upper frame members 42a and lower frame members 42b, each upper frame
member 42a being removably connected in selectable overlapping relation to
a corresponding one of the lower frame members 42b by further counterparts
of the frame fasteners 33, in rigid axial alignment therewith for forming
a middle right frame 44 and a middle left frame 46, the frames 44 and 46
being thereby adjustable in length for fitting variously sized users. The
middle right and left frames 44 and 46 are rigidly connected by a lower
bridge member 48, the bridge member 48 spacing apart the frames 44 and 46
sufficiently for generously clearing opposite sides of the user's lower
leg 14 and ankle 20. The bridge member 48 includes a left bridge portion
48a and a right bridge portion 48b, the bridge portions 48a and 48b being
removably connected in selectable rigid overlapping relation to each other
as described above in connection with the upper bridge member 38, thereby
providing adjustable spacing between the upper left and right frames 44
and 46 for accommodating the lower leg 14 of variously sized users. The
middle frame 24 is secured to the user's lower leg 14 by a further pair of
limb strap assemblies 40, designated 40c and 40d, the strap assemblies 40c
and 40d locating the upper left and right frames 44 and 46 spaced away
from opposite sides of the user's lower leg 14.
The pivotable connection of the upper frame 22 to the middle frame 24 is by
a pair of limb or knee pins 50, designated left knee pin 50a and right
knee pin 50b, which connect, in overlapping relation, the lower frame
members 32b of the upper frame 22 to the upper frame members 42a of the
middle frame 24. Each of the frame members 32b of the upper frame 22 is
formed to include an enlargement or plate member 52 having an arcuate
array of index holes 54 therein. An upper extremity of each upper frame
member 42a has a lock hole 56 whereby the middle frame 24 is lockable in a
desired angular relation with the upper frame 22 by engagement of a lock
pin 58 with the lock hole 56 and a selected one of the index holes 54 as
indicated by the dashed lines in FIG. 1. A stop pin 60 is also provided
proximate a lower extremity of the plate member 52 for preventing
hyperextension of the middle frame 24 relative to the upper frame 22 when
the lock pin 58 is not in use. Further, the lock pin 58 can be located in
a selected one of the index holes 54 but not engaging the lock hole 56,
for providing a desired range of movement. The range of movement can be
between the lock pin 58 and the stop pin 60, or between a pair of the lock
pins 58. Normally, one or a pair of the stop pins 60 is used in
corresponding locations in each of the plate members 52.
In addition to the above, a variety of adjustable restraints can be
connected between the upper frame 22 and the middle frame 24 as described
herein, such connections being made from the lower bridge member 48 and a
middle bridge member 62 that connects the plate members 52 as described
above relative to the upper bridge member 38 and the lower bridge member
48, the middle bridge member 62 also having a left bridge portion 62a and
a right bridge portion 62b for adjustably spacing the frames 22 and 24
from opposite sides of the user's knee 18. In particular, an anchor plate
64, which is rigidly connected to the middle bridge member 62 in a
plurality of selectable positions, has mounted thereto one or more eye
members 66, designated 66a, 66b, and 66c in the drawings. Similarly, one
or more eye members 68, designated 68a, 68b, and 68c, are rigidly mounted
to the lower bridge member 48, the eye members 68 also serving as the
fasteners 33 between the bridge portions 48a and 48b. One or more
extension springs 70, designated 70a, 70b, and 70c in FIG. 1, can be
hooked over the respective eyes 66 and 68 for biasing the middle frame 24
as desired toward an extension position that is aligned with the upper
frame 22, the middle frame 24 being arrested in its movement by engagement
with the stop pins 60 of the upper frame 22 as further shown in FIG. 1.
The biasing by the spring(s) 70 is further adjustable by selectively
locating the anchor plate 64 relative to the middle bridge member 62.
As shown most clearly in FIGS. 2 and 4, each of the limb strap assemblies
40 includes a pair of limb straps 72, designated outer strap 72a and inner
strap 72b, that extend in overlapping relation for enclosing the users
limb or leg 11, the overlapping portions of the straps 72 being adjustably
connected by loop and hook fastener means 74, as described herein. In
particular, the strap assemblies 40a, 40c, and 40d are configured
generally as shown in FIG. 4, the strap assembly 40b being described
further below in connection with FIG. 6. Each of the limb straps 72 has a
hook member 76 affixed along its outside face and a loop member 78 affixed
along its opposite inside face as most clearly shown in FIG. 5. For
anchoring the straps 72, an anchor strap 80 is affixed to each strap 72 by
suitable means such as by sewing and/or riveting at spaced apart locations
as indicated at 81 in FIG. 2, the anchor strap 80 extending from opposite
sides of the limb strap 72, being affixed to the adjacent frame member 32
(or 42) by a pair of strap fasteners 82, such that when tension is applied
to the connected limb strap 72, the anchor strap 80 is pulled slightly
away from the frame member 32 (or 42). Another of the loop members,
designated loop strap member 79 in the drawings, is sandwiched between the
inner strap 72b and the connected anchor strap 80, the loop member 79
extending in opposite directions from the strap 80 and engaging the hook
member 76 of the inner strap 72b for a portion of its length. The strap
fasteners 82 engage selected ones of the frame holes 37, the holes 37
being preferably uniformly spaced substantially along the full length of
the frame members 32 and 42 for interchangeably locating the bridge
members 38 and 48 and the limb strap assemblies 40, as well as for
fastening the overlapping counterparts of the frame members 32 and 42.
Each limb strap assembly 40 also includes a pad member 84 for attachment to
the inside of the inner strap 72b and an exposed portion of the outer
strap 72a, the pad member 84 having another of the hook members,
designated 77 in the drawings, affixed along an outer substrate thereof.
The pad member 84 distributes restraint force reactions about the user's
limb 11 comfortably and longitudinally on opposite sides of the loop strap
member 79.
A variation of the above described construction is used, as shown in FIG.
6, for the strap assembly 40b, for limiting lateral deflection of the
user's knee 18. A disposition for lateral knee deflection is typically
manifested in one direction only. Accordingly, the strap assembly 40b is
adapted particularly for restraining against movement in one lateral
direction, the opposite direction of restraint being obtained when
necessary by inverting the strap assembly 40b. In particular, the outer
limb strap 72a extends in one direction only about the user's limb 12 from
the anchor strap 80. Also, the inner limb strap 72b is elongated to the
point of overlapping itself. Thus, with the anchor strap 80 for the inner
limb strap 72b selectively connected to the upper frame 22 on the side
opposite the direction of potential lateral knee deflection, the strap 72b
(together with the pad member 84) is snugly connected about the user's
limb 12, the overlapping portion of the pad member 84 being tucked inside
an outside portion thereof as indicated at 86 (instead of engaging the
full length of the strap 72b). The degree of overlapping of the inner limb
strap 72b upon itself is selected for a desired degree of restraint
against the lateral movement of the user's knee 18. With the inner limb
strap 72b thus adjusted, the outer limb strap 72a is then engaged
therewith, the strap 72a being primarily employed for restraining against
forward movement of the user's limb 12 at the strap assembly 40b. (In case
restraint against rearward movement is needed, the outer strap 72a can be
reversed for extension of the strap 72a rearwardly from the anchor strap
80.)
The limb strap assemblies 40 as described above are each openable and
adjustable from both the front and the rear of the brace apparatus 10 for
facilitating attachment and removal thereof, and for obtaining proper
anterior-posterior alignment of the apparatus 10 relative to the user's
limb 12, when the user is partially or completely immobilized, as well as
for facilitating the attachment and removal by the user in appropriate
cases.
As further shown in FIGS. 1-3, the lower frame 26 includes a
foot-supporting plate or base member 88 having a pair of upstanding bars
or column members 90 rigidly mounted thereon, the column members 90 being
pivotally connected to the middle frame 24 by a pair of extremity or ankle
pins 92, designated left ankle pin 92a and right ankle pin 92b. Further
counterparts of the frame holes 37 are provided in the lower frame members
42b for receiving the ankle pins 92, these lowermost frame holes 37 being
more closely spaced than the spacing l for accurately spacing the ankle
pins 92 from the knee pins 50 according to the distance between the user's
knee 18 and ankle 20.
A base pad member 93 covers the base member 88 for comfortably supporting
the user's foot 16, the pad member 93 being protruded by the column
members 90 for facilitating the rigid connection of the column members 90
to the base member 88. Also, an inside surface of each column member 90
has a column pad 94 affixed thereto. Further the column members 90 are
each provided with a rectangular array of pin holes 95 for locating the
ankle pins 92 to match the position of the user's ankle 20 relative to the
columns 90. A pair of cleats 96, designated front cleat 96a and rear cleat
96b, are fastened to the underside of the base member 88 for support
thereof and for elevating the user's foot 16 to conventional shoe height
for ambulation. The cleats 96 are formed of a suitable resilient material
such as NEOPRENE.RTM. synthetic rubber for further cushioning of the
user's foot and for protecting floor surfaces upon which the user may
walk. The forward extremity of the base member 88 is angled upwardly for
avoiding floor contact thereby when the user's foot 16 rocks forwardly on
the front cleat 96a.
A pair of upwardly extending foot blocks 98 are rigidly connected to the
base member 88 in a plurality of selectable positions for confining a
front portion of the user's foot 16 therebetween. A front foot strap
assembly 100 is provided for securing the foot 16 against the pad member
93, opposite ends of the strap assembly 100 being selectively affixed at
one of a plurality of locations along the foot blocks 98 by a pair of
strap fasteners 102. The strap assembly 100 includes a pair of strap
members 104, designated 104a and 104b, that are adjustably connected by a
buckle or loop member 107, the strap member 104b having counterparts of
the hook and loop members 76 and 78 of the fastener means 74, designated
generally as fastener means 106, the strap member 104b being doubled back
onto itself and secured by the fastener means 106. A strap pad 108 is also
removably affixed to the strap member 104b by another counterpart of the
fastener means 106 for comfortable distribution of strap force reactions
over the user's foot 16.
Similarly, a pair of upwardly extending heel blocks 110 are rigidly
connected to the base member 88 in a plurality of selectable positions for
confining a rear portion or heel 21 of the user's foot 16 therebetween as
shown in FIGS. 1 and 7. In particular, each of the heel blocks 110 and the
base mamber 88 are formed with a plurality of heel fastener passages 111,
the passages 111 in the blocks 110 being laterally spaced differently than
the passages 111 of the base 88 for permitting a "vernier" adjustment of
the blocks 110. The heel blocks 110 are each formed to include a flange
portion 112 for fastening to the base member 88, an upstanding wall
portion 114, and an outwardly inclined ramp portion 116 for facilitating
entry of the user's heel 21. The heel 21 is held proximately in contact
with the pad member 94 by a heel strap assembly 118, opposite ends of the
strap assembly 118 extending forwardly of the column members 90 and being
rigidly connected to outside surfaces thereof by a plurality of the strap
fasteners 102. The heel strap assembly 118 includes a heel strap member
120 having a heel cup member 122, the heel cup member 122 being formed by
a downwardly extending dart connection 124 therein, and having a heel pad
126 therein for cushioning the user's heel 21. Adjustment of the heel
strap assembly 118 is effected by engagement of the strap fasteners 102
selectively in a rectangular array of threaded fastener holes 128 that are
formed in each of the column members 90. Also, the engagement of the ankle
pins 92 with selected ones of the fastener holes 128 permits the ankle
axis 30 to be located a proper distance above the base 88 for proximate
alignment with the user's ankle 20. Further, one of the lowermost frame
holes 37 is located in alignment with a corresponding one of the fastener
holes 128 when the lower frame 26 is orthogonally aligned with the middle
frame 24. Thus the lower frame 26 can be locked, when desired, in the
orthogonal position by one or more suitable fasteners (not shown).
The user's foot 16 is also retained both downwardly against the pad member
94 and rearwardly against the heel strap assembly 118 by an instep strap
assembly 130, opposite ends of which are anchored by the lowermost of the
strap fasteners 102 that also anchor the heel strap assembly 118 to the
outsides of the column members 90. The instep strap assembly 130 includes
elongated counterparts of the strap members 104a and 104b, the fastener
means 106, the loop member 107 and the strap pad member 108 of the front
foot strap assembly 100.
The lower frame 26 is also provided with an ankle strap assembly 132 for
selectively and adjustably limiting either inversion or eversion of the
user's foot 16. The ankle strap assembly 132, which also includes
counterparts of the strap members 104a and 104b, the fastener means 106,
the loop member 107 and the strap pad 108, is anchored to front and rear
edges of one of the column members 90, proximate one of the ankle pins 92,
by additional ones of the strap fasteners 102. In particular, a pair of
the fasteners 102 anchors the strap counterpart 104b to the front of the
column member 90, but only one of the fasteners 102 is used for anchoring
the strap counterpart 104a to the rear of the member 90 as further
described herein. The ankle strap assembly 132 has an ankle cup member 133
slidably fastened thereon, the cup member 133 removably carrying an ankle
pad 134 and being positioned against a selected lateral extremity of the
user's ankle 20 for preventing movement thereof in a direction away from
the column member 90 to which the ankle strap assembly 132 is anchored.
Accordingly, with the ankle strap assembly 132 connected to the column
member 90 which is visible on the right side of the brace apparatus 10 as
shown in FIG. 1, eversion of the user's right foot 16 (or inversion of the
left foot 16) is controllably prevented by appropriate adjustment of the
fastener means 106 thereof. Likewise, eversion of the user's left foot 16
(or inversion of the right foot 16) is controllably prevented with the
ankle strap assembly 132 inverted, being anchored to the column member 90
on the opposite (left) side of the lower frame 26. The use of only one of
the fasteners 102 for anchoring the strap counterpart 104a of the ankle
strap assembly 132 permits the counterpart 104a to pivot about the
fastener 102 for further facilitating proper location of the strap
assembly 132 with the ankle cup member 133 proximately centered against
the user's ankle 20.
For limiting dorsiflexion and/or plantarflexion of the lower frame 26 (and
the user's ankle 21), the brace apparatus 10 is provided with further
counterparts of the eye members 66, including at least one eye member 135
on the lower bridge member 48, and at least one eye member 136 on the
lower frame 26, the eye member 136 being mounted in one of a plurality of
locations spaced along a top edge of one or both of the foot blocks 98. As
shown in FIG. 1, one or more counterparts of the extension spring 70,
designated extension spring 138 in FIG. 1, can be hooked over the
respective eye members 135 and 136 for selectively adjustably biasing the
lower frame 26 toward a dorsiflexed position.
With further reference to FIG. 8, an upper turnbuckle 140 can be connected
between one of the eye members 66 and one of the eye members 68 for
smoothly and forcibly moving the middle frame 24 relative to the upper
frame 22. The turnbuckle 140 is advantageously effective in slowly
overcoming a contracture of the user's leg 11. Once in position, the
turnbuckle 140 can be left in place. Alternatively, the turnbuckle 140 can
be adjusted for alignment of the lock hole 56 with one of the index holes
54; then, the lock pin 58 can be used for locking the middle frame 24 in
the position obtained by the turnbuckle 140, and the turnbuckle 140 can be
disengaged or removed completely, if desired.
Similarly, a lower turnbuckle 142 can be connected between an eye member
135 of the middle frame 24 and an eye member 136 of the lower frame 26 for
smoothly and forcibly moving the lower frame 26 relative to the middle
frame 24. The turnbuckle 142 is advantageously effective in slowly
overcoming a contracture of the anterior or posterior muscles of the
user's lower leg 14.
In use, the upper and middle frames 22 and 24 are adjusted in length and
lateral spacing by appropriate selection of the frame holes 37 and bridge
holes 39 to which the frame fasteners 33 are engaged as described above,
and the strap assemblies are similarly affixed by the strap fasteners 82
in spaced apart locations on each of the upper and lower frames 22 and 26,
whereby the knee axis 28 approximately coincides with the fulcrum of the
user's knee 18, and the bottom of the middle frame 24 is slightly below
the user's ankle 20 such that one pair of the frame holes 37 is
approximately aligned with the fulcrum of the user's ankle 20. The tops of
the upper frame 22 are preferably located from approximately 2 inches to
approximately 4 inches below the top of the user's thigh. Next, the user's
foot is fitted to the lower frame 26, and the ankle pins 92 are connected
between the previously identified frame holes 37 and a pair of the pin
holes 95 of the column members 90 that are most closely aligned with the
user's ankle 20, appropriate spacers being used if necessary (and longer
counterparts of the ankle pins 92) between the lower frame members 42b and
the column members 90. The foot blocks 98 are positioned, if necessary, on
the base member 88 for accommodating the ball of the user's foot 16, and
the heel blocks 110 are similarly adjusted for receiving the user's heel
21. The adjustment of the heel blocks 110 in small increments is
facilitated by the differently spaced patterns of the heel fastener
passages 111 in the blocks 110 and in the base 88 as described above. The
location of the foot strap assembly 100 on the foot blocks 98 is adjusted,
if necessary, for locating the strap pad 108 over the ball of the user's
foot 16, not the toes. With the frames 22, 24, and 26 thus assembled, the
strap assemblies 40, 100, 118, 130 are secured and, if necessary for
support against inversion or eversion of the foot 16, the ankle strap
assembly 132 is connected and adjusted as described above. As noted above,
the upper and middle frames 22 and 24 can be secured and the strap
assemblies 40 adjusted, if necessary, with the user accessible from only
the front or the rear. Advantageously, the strap assemblies 40 locate the
frames 22 and 24 firmly, yet resiliently relative to the user's thigh 12
and lower leg 14, in that the assemblies 40b and 40c are spaced slightly
on opposite sides of the user's knee. Thus the knee pins 50 which define
the knee axis 28 suitably approximate the motion of the user's knee 18, in
that the fulcrum of the knee 18 is only approximately fixed relative to
the thigh 12 and the lower leg 14. Accordingly, the movement of the middle
frame 24 relative to the upper frame 22 accurately corresponds to the
movement of the user's knee 18, yet without binding, and without requiring
a complex knee pivot mechanism. Similarly, the location of the limb strap
assembly 40d slightly above the user's ankle 20 provides close
correspondence between movement of the lower frame 26 relative to the
middle frame 24 and movement of the user's ankle 20.
Once the frame assemblies 22, 24, and 26, are adjusted and applied as
described above, appropriate controls for movement of the user's knee 18
and ankle 20 are activated as also described above, depending on the
user's condition and the progress of therapy. Preferably several of the
springs 70 are provided for dynamic adjustment of biasing of the user's
knee 18, by selection therefrom of one, two, or three of the springs 70 to
make up a desired total of the biasing. Advantageously, only one of the
springs 70 need be tensioned and connected at a time, so that the effort
in extending and connecting any one of the springs 70 can be significantly
less than what would be required for the total of the biasing to be
supplied by only one of the springs 70. Further, the eye members 68 are
selectively locatable on the lower bridge member 48, and the eye members
66 are selectively locatable by positioning the anchor plate 64 relative
to the middle bridge member 62. Similarly, the biasing of the lower frame
26 can be by a selection of one or two from a plurality of the extension
springs 138. Moreover, the eye members 136 are selectively locatable on
the foot blocks 98, and the eye members 135 are selectively locatable on
the lower bridge member 48.
With further reference to FIG. 9, an alternative means for adjustably
biasing the middle frame 24 relative to the upper frame 22 is provided by
a tackle assembly 144 that is substituted for the eye members 68 and
springs 70 of FIG. 1. As shown in FIG. 9, a first extension spring 146 is
connected to the eye member 66c that is located on the anchor plate 64 of
the upper frame 22, the spring 146 being serially connected to a flexible
tension member or first cable 148, the cable 148 extending downwardly and
engaging the underside of a lower sheave 150 that is rotatably mounted to
the lower bridge member 48 of the middle frame 24. From the lower sheave
150, the first cable 148 extends upwardly, being serially connected to a
second extension spring 152 and a second cable 154, the cable 154 engaging
a middle sheave 156 that is rotatably mounted to the anchor plate 64. From
the middle sheave 156, the cable 154 continues upwardly to a point of
attachment with a third extension spring 158 that is also serially
connected to a third cable 160, the cable 160 passing over an upper sheave
162 that is rotatably mounted to the upper bridge member 38, from which
the third cable extends downwardly, being adjustably anchored to the
anchor plate 64 by a tackle turnbuckle 164 that is hooked to another of
the eye members, designated eye member 166, the eye member 166 being
rigidly mounted to the anchor plate 64.
The tackle assembly 144 advantageously provides a continuous adjustment of
the biasing force between the upper and middle frames 22 and 24 by means
of the tackle turnbuckle 164, the turnbuckle 164 being conveniently
located for adjustment, proximate the user's thigh 12. Similarly, the
brace apparatus 10 is advantageously adapted for donning and activation by
the user in that the tackle assembly 144 may be activated by completing
any one of the serial connections described above, such as by hooking the
tackle turnbuckle 164 onto the eye member 166. This connection is
facilitated in that the parts to be connected, such as the tackle
turnbuckle 164 and the eye member 166 are conveniently located above the
user's knee 18, and in plain view. Moreover, the connection is facilitated
by a two-to-one mechanical advantage that is associated with the lower
sheave 150.
With further reference to FIG. 10, a preferred alternative configuration of
the tackle assembly 144 has the lower sheave 150 and the upper sheave 162
mounted transversely for providing a more compact arrangement. The lower
bridge member 48 is angled slightly downwardly from the lower frame 26 for
locating the lower sheave 150 in a plane that proximately bisects the path
of the first cable 148 on opposite sides of the sheave 150. Similarly, the
middle sheave 156 and the eye member 166 locate the path of the second
cable 154 symmetrically slightly on opposite sides of the plane of the
upper sheave 162. The cables 148 and 154, which can be stranded stainless
steel cable having an outside diameter of approximately 0.06 inch,
smoothly engage the sheaves 150 and 162 by virtue of a somewhat oversize,
trough-shaped groove configuration (approximately 0.2 inch wide) of the
sheave 150 and 162. Ball-bearing wheels having an outside diameter of
approximately 1.5 inches, that are typically used for supporting
conventional sliding doors are suitable for use as the sheaves 150 and 162
in the present invention. As further shown in FIG. 10, the middle sheave
156 is rotatably mounted within a housing or block 157. The sheave 156,
having an outside diameter of approximately 1.0 inch, is readily available
assembled with the block 157 as a standard hardware item.
As also shown in FIG. 10, the stp pin 60 is relocated in the upper frame 22
above the knee axis 28, the upper frame members 42a of the middle frame 24
are formed with a rearwardly facing stop notch 61 for engaging the stop
pin 60 when the middle frame 24 is fully extended relative to the upper
frame 22.
As further shown in FIG. 10, the apparatus 10 is provided with a limit
cushion assembly 170 pivotably connected between the middle frame 24 and
the lower frame 26. The cushion assembly 170 has a flanged cylindrical
piston member 172 that threadingly engages an elongated eye member 174,
the eye member 174 being pivotably connected to one of the foot blocks 98
of the lower frame 26 by an eye screw 175. The piston member 172 slidingly
engages a sleeve member 176 that is similarly connected to the middle
frame 24 by another of the eye members 174. A limit pin 178, that rigidly
protrudes the piston member 172, extends into a longitudinal slot 180 of
the sleeve member 176. The length of the slot 180 is selected for limiting
a range of travel of the lower frame 26 about the ankle axis 30, the
relative position of the range being determined by appropriate adjustment
of the threaded engagement of the eye members 174. Further, the range of
travel is selectably adjustable according to the location of the eye screw
175 in the foot block 98. Alternatively, the limit cushion assembly 170
can be configured for adjustment of the effective length of the slot 180,
such as by a slot spacer 182 that removably engages the slot 180. The
cushion assembly 170 also includes a cushion spring 184 on the piston
member 172, the spring 184 engaging the sleeve member 176 as the upper
travel limit of the assembly 170 is approached. Thus the limit cushion
assembly 170 provides a cushioned upper travel limit to movement of the
lower frame 26 about the ankle axis 30, for walking. Typically, the
extension spring 138 is configured for biasing against downward movement
of the base member 88 below an approximately orthogonal inclination of the
base member 88 relative to the middle frame 24. The upper limit of the
cushion assembly can be set at approximately 30.degree. above the
orthogonal position, a range of free travel being provided between
inclinations at which the extension spring 138 and the cushion spring 184
are operative.
With further reference to FIGS. 11 and 12, another preferred alternative
configuration of the apparatus 10 has a dual version of the tackle
assembly 144, including a pair of the upper sheaves 162 and a pair of the
middle sheaves 156, the middle sheaves 156 each being mounted in a
corresponding block 157. As shown in FIG. 11, a spacer block 188 being
also fastened between the left and right upper bridge portions 38a and 38b
for rigidly securing the bridge member 38. In this configuration, the
first cable 148, and the lower sheave 150 are not used, two of the second
extension springs 152 being directly anchored to the lower bridge member
48 by the eye members 68a and 68b. The extension members are each
series-connected to counterparts of the second cable 154, the third
extension spring 158, and the middle sheave 156, the middle sheave 156
being tied together and anchored through single counterparts of the first
extension spring 146 and the tackle turnbuckle 164 to the eye 166. This
configuration of the tackle assembly 144 advantageously provides staged
engagement between the upper frame 22 and the middle frame 24 for
facilitating the engagement and adjustment of the tackle assembly 144,
especially by the user. The common connection through the single
turnbuckle 164 further facilitates the adjustment. Moreover, further
staged biasing connections are available from the extension springs 70a
and 70b that can be connected between the eyes 66a and 66b on the bridge
member 62 (conveniently connected into the blocks 157 as shown in FIGS. 11
and 12), and eyes 68c and 68d that are fastened on opposite sides of the
bridge 48.
Another and important advantage of the combination of the extension springs
70 with the tackle assembly 144 is that a bias profile associated with the
springs 70 is fortuitously complementary with a bias profile that is
associated with the tackle assembly 144. In particular, although the
extension springs 146, 152 and 158 of the tackle assembly 144, as well as
the extension springs 70, have an essentially linear force-deflection
characteristic, the geometry of the apparatus 10 results in a nonlinear
biasing moment about the knee axis 28. However, the nonlinearities
associated with the biasing by the tackle assembly 144 and by the
extension springs 70 tend to favorably cancel, the extension springs 70
contributing to a relatively high available biasing moment in a range of
movement at and approaching the fully extended position of the middle
frame 24 relative to the upper frame 22. This high level of available
biasing moment is particularly advantageous proximate the extended
position because conventional therapeutic apparatus such as splints
becomes ineffective when the limb 12 approaches full extension.
As further shown in FIGS. 11 and 12, another counterpart of the bridge
members, designated foot bridge 186, can be connected between the foot
blocks 98 of the lower frame 26, the foot bridge 186 having overlapping
left and right bridge members, 186a and 186b, for accommodating the
alternative spacings between the foot blocks 98 as described above in
connection with the bridge members 38, 48, and 62. The foot bridge 186
provides a convenient upper travel limit or stop for the lower frame 26,
such as by engagement of a frame fastener 33 (that connects the bridge
members 186a and 186b) against the ankle bridge 48, thereby limiting an
upward flexion of the user's foot when walking.
The adjustable configuration of the lower frame 26 advantageously adapts
the apparatus 10 for use with ambulatory patients, without requiring a
shoe of the user to be sacrificed by bolting of the shoe into the lower
frame 26. Moreover, the frame 26 can be conveniently configured for
walking with or without a shoe of the user.
Although the present invention has been described in considerable detail
with reference to certain preferred versions thereof, other versions are
possible. For example, the upper frame 22 and the middle frame 24 can be
adapted for use on the user's arm, the first hinge axis 28 functioning as
an elbow axis. Also, the eye member 166 of the tackle assembly 144 can be
relocated to the upper bridge member 48, replacing the upper sheave 162,
and permitting the tackle turnbuckle 164 to be directly connected to the
third extension spring 158, replacing the third cable 160. Further,
[turnbuckle 140 can be used to flex the knee as well as extend it with
various length turnbuckles.] Therefore, the spirit and scope of the
appended claims should not necessarily be limited to the description of
the preferred versions contained herein.
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